Incinerator

ABSTRACT

Incinerator for incinerating houshold refuse or industrial waste wherein the combustion air is blown obliquely into the incinerator through a grate at such a pressure that the refuse mass is not only fluidised by said air flow but is also transported through the incinerator. The incinerator is particularly suitable to be mounted in a refuse-collecting van so that the collected waste can be immediately incinerated and the number of return trips to a dump can be reduced to a minimum.

United States Patent 11 1 1111 3,

Du Chambon Dec. 9, 1975 [5 INCINERATOR 3,577,939 5/1971 Muirhead 110/83,589,313 6/1971 Smith et a1 110/8 [75] Inventor- 3,625,165 12/1971Ishigaki 110/28 Versallles, France 3,702,595 11/1972 Muirhead et al..110/28 .1 7 A I v. P 3,745,940 7/1973 Hibbert 110/28 3] Sslgnee gggl TheHague? 3,773,00 11/1973 B0ttaliCO.... 110/18 3,774,555 ll/1973 Turner110/8 [22] Filed: Nov. 21, 1973 Primary Examinerl(enneth W. Sprague [21]Appl' 4l8025 Attorney, Agent, or FirmMarn & Jangarathis [30] ForeignApplication Priority Data [57] ABSTRACT Nov. 24, 1972 France 72.41800Ineinerater for ineinerating houshold refuse or industrial waste whereinthe combustion air is blown [52] US. Cl. 110/8 C; 110/8 A obliquely intothe incinerator through a grate at such [51] Int. Cl. F23G 5/12 a pr surhat the refuse mass is not only fluidised by [58] Field of Search 110/8R, 8 C, 8 A, 28 J said air flow but is also transported through theincin- 110/7 R, 8 R, 18 R erator. The incinerator is particularlysuitable to be mounted in a refuse-collecting van so that the col- [56]References Cited lected waste can be immediately incinerated and theUNITED STATES PATENTS number of return trips to a dump can be reduced toa 2,959,140 11/1960 Friedberg 110/8 x 4 3,289,617 Simpson 110/7 8Claims, 3 Drawing Figures INCINERATOR This invention relates to anincinerator, in particular for incinerating household refuse andindustrial waste.

In such incinerators, the quantity of products incinerated per unit areaof fire-grate is proportional to the degree in which the products areagitated. Such agitation pulls the products apart, their useful heatexchange surface area is increased, and so is, to the same extent, therate of combustion of these products. The rate of combustion is also afunction of the rate at which air is brought into contact with theproducts. In known incinerators, the refuse is agitated mechanically,and as it is always difficult to operate a mechanical systemsatisfactorily under conditions of high and variable temperatures, theseknown constructions have never been quite satisfactory as regardsoperation and cost of maintenance. All this has also been conducive tobulky machines relative to the weight and volume that can be combustedper unit of time.

It is an object of the present invention to provide an incinerator inwhich the products are displaced without the incinerator being itselfpartly or entirely driven.

According to one aspect of the present invention, there is provided anincinerator for household refuse and industrial waste, comprising acombustion chamber having a grate, means for supplying combustion air,and filling and discharge means, characterized in that the combustionair, which is blown through said grate, is used for lifting the load ofrefuse being treated in the incinerator, whereby said load is tornapart, and brought into a fluidized state, and in which, owing to apre-determined orientation of the air, effected by said grate, thecombustion air also serves for transporting the material through theincinerator.

Thus the incinerator according to the invention is so arranged that thecombustion air flows through adapted grates under a pressure sufficientto carry and transport the products through the incinerator and toseparate the various elements of the products from one another, therebyto maximize their heat exchange surface area. The grates are mounted inthe interior of the incinerator in various ways, depending on theprocess phase and their position in terms of their functions in suchprocess phase. The local rate of flow, pressure and temperature of thecombustion air also differ in dependence on the position in thecombustion system.

Some embodiments of the invention will now be described, by way ofexample, with reference to the accompanying diagrammatic drawings, inwhich FIG. 1 is a cross-section of an incinerator according to theinvention;

FIG. 2 is a cross-section of another embodiment of the incinerator ofFIG. 2; and

FIG. 3 shows a refuse collecting van incorporating an incinerator asshown in FIGS. 1 or 2.

Referring to the drawings, an incinerator 1 is subdivided into threecombustion zones 2, 3 and 4. Each of these zones is equipped with a windbox 5, 6 and 7, respectively, bounded by grates 8, 9 and 10,respectively, having openings ll, 12 and 13, respectively, withdeflecting members disposed at an angle. A blower l4 forces air underpressure and at a pre-determined rate of flow through conduits 15, 16and 17 to boxes 5, 6 and 7. This air reaches zones 2, 3 and 4 betweenthe inclined deflecting members at a pressure sufficient to lift therefuse present in these zones, and for blowing the component elements ofthe refuse apart. In this way the refuse is brought into a fluidizedstate. Owing to the orientation of the deflecting members definingopenings 11, 12 and 13, the refuse is not only lifted, but alsodisplaced by the air from the inlet of the incinerator to the outletthereof, and this at a rate corresponding to the residence time of therefuse in each zone. The air which has flown through the refuse is ladenwith combustion gas and is discharged through a discharging, purifyingand dust separating device of a known kind. In this discharge path, theair passes boxes 18, 19, 20, 21, 22, 23 and 24, in which the combustiongases are subjected to secondary combustion. These boxes surroundfurnace l and wind boxes 5, 6 and 7, as a consequence of which the airflowing through these is pre-heated before reaching zones 2, 3 and 4.The circulation of air (mixed with combustion gas) in boxes 18-24 iscontrolled by means of valves 25, 26, 27 and 28. The refuse materialsare ignited in the furnace by means of burners 29 and 30, which areignited and extinguished under the control of known control means. Thesecondary combustion of the combustion gas can be initiated or boostedby means of burners 31 and 32, which are put into and out of operationby known control means.

In each zone the rate of flow and the pressure of the air, the numberand dimensions of the openings and the orientation of the deflectingmembers are set in dependence upon the combustion phase of the refuse tobe combusted in the zone concerned. In zone 2 the refuse is dried,pre-heated and ignited, in zone 3 the material is combusted, and in zone4 the combustion is completed, and in this zone the material isconverted into ashes.

The refuse is introduced into the furnace through a lock 33 of a knownper se kind. The ashes fall into a channel 34 by gravity whence they areintroduced into a reservoir (not shown).

In certain cases it may be of advantage to prepare the material prior tointroducing it into the incinerator by subjecting it to tearing andcrushing operations.

In the modification shown in FIG. 2, the furnace has three chambersmounted one on top of the other, and each corresponding with acombustion zone.

The grates, formed with openings and deflecting members, can beconstructed in the form of a mosaic of elements placed side by side withexpansion joints between them. These elements may have the form ofcorrugated sheets.

The incinerator according to the invention can be constructed of light,metallic elements (thin, profiled sheet steel), which permits a largevariation in size. Such an incinerator can be the basic element of botha mobile unit and a large-capacity incinerator plant. The apparatusaccording to the invention also lends itself extremely well for anincinerator unit at the end of a pneumatic household-refuse chute.

FIG. 3 shows a refuse-collecting van accommodating an incineratoraccording to FIGS. 1 or 2. Such a van has the advantage that, since therefuse is combusted as it is collected in the streets, it is much lessfrequently necessary to travel to a dump to discharge the materialcollected. 5

I claim:

1. An incinerator for household refuse, industrial waste, and likematerial, comprising a combustion chamber having a stationary gratemeans, means for supplying combustion air through said grate means, andfilling and discharge means, characterized in that said grate meansincludes deflecting members for directing said combustion air in amanner to lift said material being treated in the incinerator wherebysaid material is torn apart and brought into a fluidized state, andwhereby owing to a pre-determined orientation of the air effected bysaid grate means, the combustion air also serves to transport saidmaterial through said incmerator.

2. Apparatus according to claim 1, wherein the furnace is divided into aplurality of combustion zones, each zone having a supply of air ofdifferent rate of flow, pressure and temperature, and each zone havinggrate openings and deflecting means adapted to the function of suchzone.

3. Apparatus according to claim 1 wherein the furnace and at least partof said means for supplying combustion air is surrounded by secondarycombustion chambers for the secondary combustion of a combustion gaswithdrawn from said furnace so that said combustion air is preheatedthrough heat exchange between said secondary combustion chambers andsaid means for supplying combustion air.

4. Apparatus according to claim 3, wherein the gas circulation in saidsecondary-combustion chambers is controlled by valves.

5. Apparatus according to claim 2 wherein said combustion zones arelocated one behind the other, and said furnace is tunnel-shaped.

6. Apparatus according to claim 2 wherein the cornbustion zones arelocated one above the other.

7. Apparatus according to claim 1 characterized by means in said fillingmeans for comminuting the refuse.

8. A refuse-collecting van provided with an incinerator as claimed inclaim 1.

1. An incinerator for household refuse, industrial waste, and like material, comprising a combustion chamber having a stationary grate means, means for supplying combuStion air through said grate means, and filling and discharge means, characterized in that said grate means includes deflecting members for directing said combustion air in a manner to lift said material being treated in the incinerator whereby said material is torn apart and brought into a fluidized state, and whereby owing to a pre-determined orientation of the air effected by said grate means, the combustion air also serves to transport said material through said incinerator.
 2. Apparatus according to claim 1, wherein the furnace is divided into a plurality of combustion zones, each zone having a supply of air of different rate of flow, pressure and temperature, and each zone having grate openings and deflecting means adapted to the function of such zone.
 3. Apparatus according to claim 1 wherein the furnace and at least part of said means for supplying combustion air is surrounded by secondary combustion chambers for the secondary combustion of a combustion gas withdrawn from said furnace so that said combustion air is pre-heated through heat exchange between said secondary combustion chambers and said means for supplying combustion air.
 4. Apparatus according to claim 3, wherein the gas circulation in said secondary-combustion chambers is controlled by valves.
 5. Apparatus according to claim 2 wherein said combustion zones are located one behind the other, and said furnace is tunnel-shaped.
 6. Apparatus according to claim 2 wherein the combustion zones are located one above the other.
 7. Apparatus according to claim 1 characterized by means in said filling means for comminuting the refuse.
 8. A refuse-collecting van provided with an incinerator as claimed in claim
 1. 